A. Field of the Invention
This invention relates to fluid distribution systems for fluid separation modules.
B. Prior Art
In one type of fluid separation apparatus, a bundle of membranes in the form of hollow fibers is potted in a resinous tube sheet, the resinous tube sheet being made from an epoxy or other material which is allowed to cure to a solid state. The potting of the fiber bundle in the tube sheet is carried out by placing the end of the fiber bundle in a mold and then pouring in a casting resin to fill the mold and the spaces between the fibers making up the bundle. Because of the fact that some of the casting resin wicks along the fibers and the fact that those portions of the fibers adjacent to the tube sheet are subjected to the heat generated in the exothermic curing of the tube sheet, the hollow fiber membranes tend to be most fragile at points in close proximity to the face from the tube sheet of which the fibers extend.
U.S. Pat. Nos. 4,378,981 and 4,380,460 disclose fluid separation modules having a fluid distribution system intended to reduce the erosion of fibers in a bundle of hollow fiber membranes by controlling the entrance of the fluid into the fiber bundle. A major disadvantage of these distribution systems is that the fluid is permitted to enter the fiber bundle in a radial direction with respect to the bundle such that the velocity of the fluid transverse to the hollow fiber membranes is at a maximum.
U.S. Pat. No. 3,339,341 is one of several patents which disclose the use of a fabric sleeve surrounding a bundle of hollow filaments used as membranes for separating fluids. The primary purpose of the fabric sleeve is to compact the fiber bundle when tension is applied to the sleeve so as to make the assembly of the bundle in a cylindrical shell easier. The diameter of the sleeve is such that the fiber bundle is in contact with the shell in normal operation.
U.S. Pat. No. 3,526,001 discloses a bundle of hollow fiber membranes encased in a fabric sleeve which is put under tension to compact the fiber bundle for insertion into a shell. The diameter of the sleeve is such that the bundle of fibers expands to fill the shell under operating conditions.